Explicação passo-a-passo:
[tex]a) \frac{1}{2} \times \frac{2}{3} \div \frac{1}{3} = \frac{2}{6} \div \frac{1}{3} = \frac{2}{6} \times 3 = \frac{6}{6} = 1[/tex]
[tex]b) \frac{2}{4} \div \frac{1}{5} = \frac{2}{4} \times 5 = \frac{10}{4} = \frac{5}{2} [/tex]
[tex]c) \frac{4}{7} - \frac{6}{2} = \frac{4}{7} - 3[/tex]
[tex] \frac{4 - 21}{7} = \frac{ - 17}{7} [/tex]
